POSTN and obstructive sleep apnea syndrome: Compared with the severe OSA alone group (n = 41), the severe OSA with high periostin group (n = 12) exhibited significantly higher free fatty acid levels (p = 0.03) and prevalence of albuminuria (p = 0.04) (Table 4) and a trend for more frequent DM (p = 0.07) and asthma (p = 0.06).